1. Field
The subject matter disclosed herein relates to electronic devices, and more particularly to methods, apparatuses and articles of manufacture for use in characterizing an area of location uncertainty within an indoor structure based on detected movements and/or position locations of a mobile device.
2. Information
The Global Positioning System (GPS) represents one type of Global Navigation Satellite System (GNSS), which along with other types of satellite positioning systems (SPS) provide or otherwise support signal-based position location capabilities (e.g., navigation functions) in mobile devices, and particularly in outdoor environments. However, since some satellite signals may not be reliably received and/or acquired by a mobile device within an indoor environment, different techniques may be employed to enable position location services.
For example, mobile devices may attempt to obtain a position fix by measuring ranges to three or more terrestrial transmitters (e.g., wireless access point devices, beacons, cell towers, etc.) which are positioned at known locations. Such ranges may be measured, for example, by obtaining a MAC ID address from signals received from such transmitters and obtaining range measurements to the transmitters by measuring one or more characteristics of signals received from such transmitters such as, for example, signal strength, a round trip time delay, etc.
These and other like position location and navigation techniques tend to be of further benefit to a user if presented with certain mapped features. For example, mapped features may relate to or otherwise identify certain physical objects, characteristics, or points of interest within a building or complex, etc. Thus, in certain instances, an indoor navigation system may provide a digital electronic map to a mobile device upon entering a particular indoor area, e.g., in response to a request for position assistance data. Such a map may show indoor features such as doors, hallways, entry ways, walls, etc., points of interest such as bathrooms, pay phones, room names, stores, etc. Such a digital electronic map may be stored at a server to be accessible by a mobile device through selection of a URL, for example. By obtaining and displaying such a map, a mobile device may overlay a current location of the mobile device (and user) over the displayed map to provide the user with additional context.
In certain instances, some of the information that may be provided to and/or otherwise used by a mobile device for navigational or other like purposes may change from time to time, or may even be unknown. Thus, it may be useful to determine whether such information may have changed, or to otherwise gather and/or develop such information in an efficient manner.